Finger/palm-print image processing apparatus, finger/palm-print image processing method, and recording medium in which finger/palm-print image processing program has been recorded

• US 8,457,369 B2
• Filed: 12/22/2009
• Issued: 06/04/2013
• Est. Priority Date: 12/22/2008
• Status: Active Grant

• Current Assignee: NEC Solution Innovators, Ltd (NEC Corporation)
• Original Assignee: NEC Corporation, NEC Software Chubu Limited (NEC Corporation)
• Inventors: Nakada, Satoshi, Horiba, Yuji, Kondo, Masanori, Kanayama, Akira
• Primary Examiner(s): Seth, Manav
• Application Number:
  US13/133,712
• Publication Number:
  US 20110249873A1
• Time in Patent Office: 1,260 Days
• Field of Search: None
• US Class Current: 382/124
• CPC Class Codes: G06T 7/44 using image operators, e.g. filters, edge density metrics or local histograms
• CPC Class Codes: G06V 10/993 Evaluation of the quality of the acquired pattern
• CPC Class Codes: G06V 40/1347 Preprocessing; Feature extraction

Abstract

A finger/palm-print image processing apparatus comprises: an image converting means that converts finger/palm-print images to conversion images consisting of first and second sets of elements; and an area detecting means that detects, from the conversion images as converted by the image converting means, an area where the number of the first set of elements is equal to or greater than a predetermined number. The first and second sets of elements herein are the elements of sets each of which consists of elements of the finger/palm-print images. The first set of elements have those degrees of change in color information which meet a predetermined criterion, while the second set of elements have those degrees of change in color information which do not meet the predetermined criterion.

Claims

1. A finger/palm-print image processing apparatus for processing a finger/palm-print image that is an image of a finger/palm-print, the finger/palm-print image processing apparatus comprising:

an image converting unit for converting the finger/palm-print image into a converted image having sets in which elements of the finger/palm-print image are gathered and comprising a first set of elements in which the degree of change in color information in the elements within the set of elements satisfy a predetermined criterion, and a second set of elements in which the degree of change in color information in the elements within the set of elements do not satisfy a predetermined criterion; and

a region detecting unit for selecting a region that is a part of the converted image converted by the image converting unit, determining whether or not a selected region that is the region that was selected contains at least a prescribed number of the first set of elements, and detecting the selected region as a region with at least a prescribed number of the first set of elements only when at least the prescribed number are contained;

wherein the region detecting unit selects a region on the right side of the selected region as a second selected region when the selected region is on the left side of the converted image, and from there reselects regions surrounding the selected regions until a predetermined number of regions containing at least a predetermined number of the first set of elements is detected in a counterclockwise direction; and

selects a region on the left side of the selected region as a second selected region when the selected region is on the right side of the converted image, and from there reselects regions surrounding the selected regions until a predetermined number of regions containing at least a predetermined number of the first set of elements is detected in a clockwise direction.

2. The finger/palm-print image processing apparatus according to claim 1, wherein the region detecting unit selects a region that is part of the converted image by selecting a region containing one of multiple points set respectively in multiple prescribed positions mutually separated within the converted image.

3. The finger/palm-print image processing apparatus according to claim 2, wherein the region detecting unit selects a region in a position on the inside of the finger/palm-print image from the point when reselecting a region that is part of the converted image.

4. The finger/palm-print image processing apparatus according to claim 2, wherein the region detecting unit selects a region in a position on the inside of the finger/palm-print image from the point when reselecting a region that is part of the converted image, and from that initially reselects the region so as to encompass the surroundings of the point in a direction facing the inside of the finger/palm-print image.

5. The finger/palm-print image processing apparatus according to claim 2, wherein the multiple points are set within a prescribed range in the converted image.

6. A finger/palm-print image processing method for processing a finger/palm-print image that is an image of a finger/palm-print, including the following steps:

converting the finger/palm-print image into a converted image having sets in which elements of the finger/palm-print image are gathered and comprising a first set of elements in which the degree of change in color information in the elements within the set of elements satisfy a predetermined criterion, and a second set of elements in which the degree of change in color information in the elements within the set of elements do not satisfy a predetermined criterion; and

selecting a region that is a part of the converted image, determining whether or not a selected region that is the region that was selected contains at least a prescribed number of the first set of elements, and detecting the selected region as a region with at least a prescribed number of the first set of elements only when at least the prescribed number are contained;

a region on the right side of the selected region is selected as a second selected region when the selected region is on the left side of the converted image, and from there regions surrounding the selected regions are reselected until a predetermined number of regions containing at least a predetermined number of the first set of elements is detected in a counterclockwise direction; and

a region on the left side of the selected region is selected as a second selected region when the selected region is on the right side of the converted image, and from there regions surrounding the selected regions are reselected until a predetermined number of regions containing at least a predetermined number of the first set of elements is detected in a clockwise direction.

7. A non-transitory recording medium on which is recorded a finger/palm-print image processing program for accomplishing on a computer a finger/palm-print image processing method for processing a finger/palm-print image that is an image of a finger/palm-print, wherein the recording medium records a finger/palm-print image processing program comprising:

an image converting step for converting the finger/palm-print image into a converted image having sets in which elements of the finger/palm-print image are gathered and comprising a first set of elements in which the degree of change in color information in the elements within the set of elements satisfy a predetermined criterion, and a second set of elements in which the degree of change in color information in the elements within the set of elements do not satisfy a predetermined criterion; and

a region detecting step for selecting a region that is a part of the converted image converted by the image converting step, determining whether or not a selected region that is the region that was selected contains at least a prescribed number of the first set of elements, and detecting the selected region as a region with at least a prescribed number of the first set of elements only when at least the prescribed number are contained;

wherein the region detecting step a region on the right side of the selected region is selected as a second selected region when the selected region is on the left side of the converted image, and from there regions surrounding the selected regions are reselected until a predetermined number of regions containing at least a predetermined number of the first set of elements is detected in a counterclockwise direction; and

a region on the left side of the selected region is selected as a second selected region when the selected region is on the right side of the converted image, and from there regions surrounding the selected regions are reselected until a predetermined number of regions containing at least a predetermined number of the first set of elements is detected in a clockwise direction.